Oh my aching gut: irritable bowel syndrome, Blastocystis, and asymptomatic infection.

Blastocystis is a prevalent enteric protozoan that infects a variety of vertebrates. Infection with Blastocystis in humans has been associated with abdominal pain, diarrhea, constipation, fatigue, skin rash, and other symptoms. Researchers using different methods and examining different patient groups have reported asymptomatic infection, acute symptomatic infection, and chronic symptomatic infection. The variation in accounts has lead to disagreements concerning the role of Blastocystis in human disease, and the importance of treating it. A better understanding of the number of species of Blastocystis that can infect humans, along with realization of the limitations of the existing clinical laboratory diagnostic techniques may account for much of the disagreement. The possibility that disagreement was caused by the emergence of particular pathogenic variants of Blastocystis is discussed, along with the potential role of Blastocystis infection in irritable bowel syndrome (IBS). Findings are discussed concerning the role of protease-activated receptor-2 in enteric disease which may account for the presence of abdominal pain and diffuse symptoms in Blastocystis infection, even in the absence of fever and endoscopic findings. The availability of better diagnostic techniques and treatments for Blastocystis infection may be of value in understanding chronic gastrointestinal illness of unknown etiology.

Transmission of Dientamoeba fragilis: evaluation of the role of Enterobius vermicularis.

The role of Enterobius vermicularis in the transmission of Dientamoeba fragilis has been evaluated in two groups of patients admitted to the Parasitology Laboratory of Celal Bayar University: one group with E. vermicularis infection (n=187, Pinworm Group), and the other with D. fragilis infection (n=126, Dientamoeba Group). The presence of the other parasite, pinworm or Dientamoeba, was investigated with the microscopic examination of cellophane tape and stool samples for three consecutive days. In the Pinworm Group, 9.6% of the patients were found to be coinfected with D. fragilis, while 25.4% of the patients in the Dientamoeba Group were found to be coinfected with pinworms. The coincidence rates of D. fragilis and E. vermicularis, higher than the prevalence of each parasite in similar populations, suggest a common relation between these two parasites, possibly in entering the human body. E. vermicularis infection was found to be significantly more common in younger children (p<0.001), indicating that younger children may also be at higher risk for D. fragilis infection. These findings also raise the question of whether the unrelated symptoms of the pinworm infected patients such as abdominal pain and diarrhea may actually be due to overlooked Dientamoeba infections.

Health inequities: lower socio-economic conditions and higher incidences of intestinal parasites.

BACKGROUND: Intestinal parasitic infections affect child health and development and slow down growth, while reducing adults' productivity and work capacity. The aim of the present study was to determine and compare the incidences of intestinal parasitic infections and the socio-economic status of two near primary school children in Manisa, a western city of Turkey. METHODS: A total of 352 children were involved a questionnaire study from a private school (Ulkem Primary School - UPS, 116 children) and a community-based school (Sehzadeler Primary School - SPS, 236 children). Of these, stool samples could be obtained from a total of 294 students; 97 (83.6%) from UPS, and 197 (83.5%) from SPS. The wet mount preparations of the stool samples were examined; samples were also fixed in polyvinyl alcohol and examined with modified formalin ethyl acetate sedimentation and trichrome staining techniques. Data were analyzed using SPSS for Windows version 10.0. The chi-squared test was used for the analytic assessment. RESULTS: The percentages of the students found to be infected with intestinal parasites, were 78 (39.6%) and 13 (13.4%) in SPS and UPS, respectively. Totally 91 (31.0%) of the students from both schools were found to be infected with at least one intestinal parasite. Giardia lamblia was found to be the most common pathogenic intestinal parasite and Blastocystis hominis was prevalent independently from the hygienic conditions. The factors which significantly (p < 0.05) increase the incidence of intestinal parasites were uneducated and unemployed mother, lower social status of father, living in crowded houses with insufficient indoor spaces, using the tap water as drinking water, and living at shanty areas. CONCLUSION: Intestinal parasitic infections in school children were found to be a public health problem that increased due to lower socio-economic conditions. We conclude that organization of education seminars including the topics such as prevention of the infectious diseases, improving general hygienic conditions, and application of supportive programs for the parents may be suggested not only to reduce intestinal parasitic infections, but also to elevate the socio-cultural levels.

A province-based study using sampling method to investigate the prevalence of cystic echinococcosis among primary school children in Manisa, Turkey.

A province-based field study using a portable ultrasound scanner (US) was performed for the first time using sampling method to investigate the prevalence of cystic echinococcosis (CE) in primary school children in Manisa, Turkey. A total of 6093 children from 37 primary schools was selected as the representative sample of the total number of 166,766 primary school children, and examined by the US. Prevalence was found to be 0.15%, as nine children were diagnosed with CE, seven new and two previously operated. A questionnaire applied to the children revealed no significant relationship between the risk factors and the infection (P>0.05). In conclusion, it would be advisable to repeat the study at the same schools in eight years' time, in order to evaluate the efficacy of the control programs, since nearly all students involved in this study will have graduated by then. Besides, it is recommended to choose a sampling group to find the prevalence of an infection in a defined region.

The value of ultrasonography alone in screening surveys of cystic echinococcosis in children in Turkey.

A total of 1,205 primary school children were examined for cystic echinococcosis in five villages of Manisa, Turkey, to evaluate the efficacy of diagnostic methods of this infection in community-based screening surveys. Six hundred and thirty children from three villages, examined by a portable ultrasound scanner, chest microfilm and serological methods (ELISA, indirect hemagglutination) in our previous study, were designated as Study Group 1; and 575 children, from two adjacent villages, examined by ultrasonography alone in the present study, were designated as Study Group 2. In Study Group 1, hepatic cystic echinococcosis was detected in two cases (0.3%) by ultrasonography, while 43 (8.9%) and 49 (10.1%) cases were found to be positive for cystic echinococcosis by ELISA and indirect hemagglutination, respectively. Three of 575 children (0.5%) were diagnosed with cystic echinococcosis (two hepatic and one renal involvement) by ultrasonography alone in Study Group 2; and lung lesions were later detected in both cases with liver involvement by chest radiography. Our results suggested that serological tests may be beneficial in suspected cases for confirmation and differential diagnosis, but have some drawbacks, such as discrepancy in results and high false seropositivity rates. Chest microfilm is not easy in field studies and exposure to X-ray is undesirable. As a reliable, simple, inexpensive and rapid technique, ultrasonography alone is recommended to be used in community-based screening surveys for cystic echinococcosis with confirmatory tests for suspected cases found during the screening program.

A discrepancy between cystic echinococcosis confirmed by ultrasound and seropositivity in Turkish children.

In three randomly selected villages of Manisa, Turkey, 630 primary school children were examined for cystic echinococcosis (CE) by a portable ultrasound scanner (US) and chest microfilm. Sera samples of 483 (76.7%) children were tested for anti-E. granulosus antibodies by ELISA and indirect hemagglutination (IHA) tests. Hepatic CE were detected in two cases (0.3%) by US, while 43 (8.9%) and 49 (10.1%) cases were found to be positive for CE by ELISA and IHA, respectively. The high seropositivity levels could have been attributed to extra-abdominal or abortive Echinococcus infections, but probably most of them were false-positives. Due to the discrepancy in results, US should be selected as the primary test in field studies and serologic tests should be performed in all cases with suspected lesions. We could not find any reported community based study on CE in Turkey, in which US was applied; but our results suggest that extensive epidemiological studies are required.

Giardiasis treatment in Turkish children with a single dose of ornidazole.

This study was designed to compare the treatment efficacy of single dose of ornidazole with 5 d treatments of ornidazole and metronidazole in children with giardiasis. 175 children, between 2 and 15 y old, whose stool samples were found to be positive for Giardia lamblia cysts and/or trophozoites by either saline-Lugol, formalin-ethyl acetate or trichrome staining, were enrolled in the study. Of these children, 105 were treated with a single dose of ornidazole: 35 with 30 mg/kg, 35 with 25 mg/kg and 35 with 20 mg/kg; 35 were treated with 25 mg/kg per day of ornidazole for 5 d in 2 doses and 35 children were treated with 20 mg/kg per day metronidazole for 7 d in 3 doses. All cases were examined on the 7th, 10th and 14th days after treatment by the same methods; clinical symptoms were also evaluated. Giardia lamblia was eradicated in 34 of 35 (97%), 34 of 35 (97%) and 33 of 35 (94%) patients treated with 30, 25 and 20 mg/kg single doses of ornidazole, respectively. Eradication was achieved in all 35 patients treated with 25 mg/kg per day ornidazole for 5 d and in 31 of 35 (89%) patients treated with metronidazole. There was no statistically significant difference among doses of ornidazole (p > 0.05); however, all ornidazole treatment regimens were significantly more effective than metronidazole treatment (p < 0.05). No important side-effects were detected in any patients and clinical symptoms disappeared in all. Single-dose ornidazole treatment could be considered as a proper and effective alternative method for the treatment of giardiasis in children.